Allow passing multiple redirect URIs to Dex

We need this in CI when we want to configure Dex with the redirect URI for both
primary and secondary deploys at one time (since we only stand up Dex once).

Signed-off-by: Andrew Keesler <akeesler@vmware.com>

test/deploy/dex/dex.yaml

@@ -1,4 +1,4 @@
-#! Copyright 2020 the Pinniped contributors. All Rights Reserved.
+#! Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
 #! SPDX-License-Identifier: Apache-2.0
 
 #@ load("@ytt:data", "data")
@@ -27,8 +27,7 @@ staticClients:
 - id: pinniped-supervisor
   name: 'Pinniped Supervisor'
   secret: pinniped-supervisor-secret
-  redirectURIs:
-  - #@ data.values.supervisor_redirect_uri
+  redirectURIs: #@ data.values.supervisor_redirect_uris
 enablePasswordDB: true
 staticPasswords:
 - username: "pinny"
@@ -114,4 +113,3 @@ spec:
   - name: https
     port: 443
     targetPort: 8443
-